The present invention relates to a magnetic head slider, a support therefor and a magnetic disk unit, and more particularly to a magnetic head slider, a support therefor and a magnetic disk unit that are excellent for enhancing a recording density and reliability.
In magnetic disk units, demands for higher reliability on a head-disk interface and for minimization on a flying height are growing more and more exacting in recent years.
As a surface recording density increases year by year, a required flying height tends to decrease. Particularly when the flying height is less than 30 nm, a possibility arises that a head will be in intermittent or continuous contact with a media surface.
A measure to solve this problem is to reduce a flying height hto at the beginning of contact of a slider surface with the media surface, thereby increasing a flying margin. A possible factor contributing to increasing the flying height hto at the beginning of contact with the media surface is deemed to be large changes in the flying height with respect to a media surface waviness of a sufficiently large wavelength as compared with a slider length and a microwaviness of a wavelength almost equal to the slider length.
A conventional flying-recording type magnetic head slider described in JP-A-6-325530 is comprised of a air bearing surface, which may contact a media surface when the disk is at rest and serve as an air bearing surface, and a stepped surface bounded on the air bearing surface in an air inflow direction with a step therebetween.
The depth δs of the step is less than 500 nm, and a ratio between a length L of the slider in the air inflow direction and a width W thereof in a direction perpendicular to the air inflow direction is 0.3 or less. This construction realizes a flying characteristic that keeps the flying height from changing when a circumferential speed changes.
A conventional magnetic head slider disclosed in U.S. Pat. No. 5,777,825 is comprised of two air-bearing pads formed on the inflow side, another air-bearing pad on the outflow side, and two side rails formed along both lateral sides.
A subambient pressure force generated in a region enclosed by the air-bearing pads and side rails enables a reduction of flying height changes due to atmospheric pressure fluctuations around the slider to be reduced.